Disposable pump chamber for an infusion pump

Abstract

An apparatus, including a pump body having an internal shaft, and a piston disposed within the shaft and having a piston head that includes a first ferromagnetic element. The apparatus also includes a motor coupled to drive a reciprocal longitudinal motion of the piston within the shaft, and a pump chamber configured to be removably attached to the pump body and having a rigid wall defining a fluid inlet, a fluid outlet, and an aperture. The apparatus additionally includes a flexible diaphragm fixed across the aperture and having a second ferromagnetic element, which engages the first ferromagnetic element when the pump chamber is attached to the pump body so that the reciprocal longitudinal motion of the piston causes alternating stretching and contraction of the flexible diaphragm, thereby modifying a volume of the pump chamber.

1 . A method, comprising:
 providing a pump body comprising an internal shaft;   providing a piston disposed within the shaft and having a piston head comprising a first ferromagnetic element;   coupling, to the piston, a motor in order to drive a reciprocal longitudinal motion of the piston within the shaft;   providing a pump chamber configured to be removably attached to the pump body and comprising a rigid wall defining a fluid inlet, a fluid outlet, and an aperture; and   affixing, across the aperture, a flexible diaphragm comprising a second ferromagnetic element, which engages the first ferromagnetic element when the pump chamber is attached to the pump body so that the reciprocal longitudinal motion of the piston causes alternating stretching and contraction of the flexible diaphragm, thereby modifying a volume of the pump chamber.   
     
     
         2 . The method according to  claim 1 , wherein the first ferromagnetic element comprises a permanent magnet, and wherein the second ferromagnetic element comprises a metal with ferromagnetic properties. 
     
     
         3 . The method according to  claim 1 , wherein the first ferromagnetic element comprises a metal with ferromagnetic properties, and wherein the second ferromagnetic element comprises a permanent magnet. 
     
     
         4 . The method according to  claim 1 , wherein the first and the second ferromagnetic elements comprise respective permanent magnets. 
     
     
         5 . The method according to  claim 1 , wherein at least one of the ferromagnetic elements comprises an electromagnet. 
     
     
         6 . The method according to  claim 1 , and comprising providing a medical irrigation system coupled to the motor, and a processor configured to control the medical irrigation system. 
     
     
         7 . The method according to  claim 1 , and comprising providing an irrigation catheter coupled to the fluid outlet. 
     
     
         8 . The method according to  claim 1 , wherein the pump chamber is disposable. 
     
     
         9 . The method according to  claim 1 , wherein a pump defined by the pump chamber and the flexible diaphragm is self-priming.